add commented suggestions

Author: Daniel Flores

src/torchcodec/_core/Encoder.cpp

@@ -527,7 +527,7 @@ torch::Tensor validateFrames(const torch::Tensor& frames) {
       frames.sizes()[1] == 3,
       "frame must have 3 channels (R, G, B), got ",
       frames.sizes()[1]);
-  // TODO-VideoEncoder: Investigate if non-contiguous frames can be returned
+  // TODO-VideoEncoder: Investigate if non-contiguous frames can be accepted
   return frames.contiguous();
 }
 
@@ -593,9 +593,6 @@ void VideoEncoder::initializeEncoder(
         *desiredBitRate >= 0, "bit_rate=", *desiredBitRate, " must be >= 0.");
   }
   avCodecContext_->bit_rate = desiredBitRate.value_or(0);
-  // TODO-VideoEncoder: Verify that frame_rate and time_base are correct
-  avCodecContext_->time_base = {1, inFrameRate_};
-  avCodecContext_->framerate = {inFrameRate_, 1};
 
   // Store dimension order and input pixel format
   // TODO-VideoEncoder: Remove assumption that tensor in NCHW format
@@ -618,7 +615,9 @@ void VideoEncoder::initializeEncoder(
   avCodecContext_->width = outWidth_;
   avCodecContext_->height = outHeight_;
   avCodecContext_->pix_fmt = outPixelFormat_;
+  // TODO-VideoEncoder: Verify that frame_rate and time_base are correct
   avCodecContext_->time_base = {1, inFrameRate_};
+  avCodecContext_->framerate = {inFrameRate_, 1};
 
   // TODO-VideoEncoder: Allow GOP size and max B-frames to be set
   if (videoStreamOptions.gopSize.has_value()) {
@@ -726,6 +725,7 @@ UniqueAVFrame VideoEncoder::convertTensorToAVFrame(
   // TODO-VideoEncoder: Reorder tensor if in NHWC format
   int channelSize = inHeight_ * inWidth_;
   // Reorder RGB -> GBR for AV_PIX_FMT_GBRP format
+  // TODO-VideoEncoder: Determine if FFmpeg supports RGB input format directly
   inputFrame->data[0] = tensorData + channelSize;
   inputFrame->data[1] = tensorData + (2 * channelSize);
   inputFrame->data[2] = tensorData;

src/torchcodec/_core/Encoder.h

@@ -140,7 +140,6 @@ class VideoEncoder {
       int frameIndex);
   void encodeFrame(AutoAVPacket& autoAVPacket, const UniqueAVFrame& avFrame);
   void flushBuffers();
-  void close_avio();
 
   UniqueEncodingAVFormatContext avFormatContext_;
   UniqueAVCodecContext avCodecContext_;

test/test_ops.py

@@ -1229,7 +1229,7 @@ def test_bad_input(self, tmp_path):
 class TestVideoEncoderOps:
 
     def test_bad_input(self, tmp_path):
-        output_file = str(tmp_path / ".mp3")
+        output_file = str(tmp_path / ".mp4")
 
         with pytest.raises(
             RuntimeError, match="frames must have uint8 dtype, got float"